1. Causes of climate change
1. Enhanced greenhouse effect
Increase in use of fossil fuels in vehicles, factories and power plants lead to release of
more CO2 and NOx since industrialisation began.
Increase in use of chemicals (eg. CFCs) contribute to enhanced greenhouse effect
because of the presence of carbon compounds in CFCs.
Large-scale deforestation and forest fires have reduced veg cover for timber and mining
and to create more land to fulfil demand. With this, overall photosynthesis is reduced and
less CO2 is absorbed.
Agricultural activities also contribute. Wet rice cultivation, use of inorganic fertilisers
and cattle ranching via release after digestive processes produce a lot of CH4 and NOx.
Effects of climate change
1. Melting ice and rising sea levels
When temperature rises, it melts the ice caps that are found in the Arctic and Antarctic
regions. Glaciers have been retreating and the amount of ice cover has decreased in the
polar regions, causing the sea levels to rise. Low lying coastal countries (eg. Bangladesh)
are vulnerable to rising sea levels and the chances of flooding in these areas are greatly
increased.
2. Severe storms
Regions with wetter climates like China, SEA and the western USA will experience
higher RH then higher global temperatures and higher evaporation rates, which increases
rainfall in these places, leading to floods. Warmer ocean temperatures also cause more
intense tropical storms to form. More devastating hurricanes bring more damage to the
property and infrastructure and also affect the economy.
3. Heat waves and droughts
Regions with drier climates like the Sahel region will experience droughts when
temperatures increase. Vegetation will dry up causing forest fires to occur frequently.
Water sources will dry up easily as rate of evaporation is high. Heat waves like the one in
Milan, Italy in 2003 at 32.7°C caused many deaths.
4. Impact on plants and animals
Increasing temperatures causes changes in the flowering patterns of plants (eg. European
plants flower earlier by 1 week, shed leaves earlier by 1 week) and breeding patterns of
animals. Warmth encourages rapid breeding of insects like mosquitoes leading to spread

2. of diseases such as malaria. Animals are forced to migrate or not be faced by extinction.
(eg. Population of Adelie penguins in Biscoe islands has reduced from 2800 to 1000 pairs)
Reducing impacts of climate change
1. Mitigation
Signing international agreements (eg. Kyoto Protocol) to reduce emissions of greenhouse
gases help to reduce amount of greenhouse gases in the atmosphere. In Singapore, a
compulsory smoke emission test and the fitting of catalytic converters must be done to all
cars.
2. Adaptation
Relocating people away from low-lying coastal areas and prohibition of new construction
or development in these locations help to reduce risk of loss of lives or damage to
property.